Symbol editor: ensure a new derived symbol has the correct DeMorgan option displayed.

Derived symbols use the same graphics as their parent, so ensure the parent is
used to enable/disable the DeMorgan option and tool in toolbar
Fixes #13739
https://gitlab.com/kicad/code/kicad/-/issues/13739

eeschema/symbol_editor/symbol_editor.cpp

@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2019 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2008 Wayne Stambaugh <stambaughw@gmail.com>
- * Copyright (C) 2004-2022 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2004-2023 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -486,7 +486,11 @@ void SYMBOL_EDIT_FRAME::CreateNewSymbol( const wxString& inheritFromSymbolName )
 
     // must be called after loadSymbol, that calls SetShowDeMorgan, but
     // because the symbol is empty,it looks like it has no alternate body
-    SetShowDeMorgan( dlg.GetAlternateBodyStyle() );
+    // and a derived symbol inherits its parent body.
+    if( !new_symbol.GetParent().lock() )
+        SetShowDeMorgan( dlg.GetAlternateBodyStyle() );
+    else
+        SetShowDeMorgan( new_symbol.HasConversion() );
 }